- function as or act like;
"This heap of stones will act as a barrier"
- pretend to have certain qualities or state of mind;
"He acted the idiot"
"She plays deaf when the news are bad"
- I must find someone to act as a deputy for me during my absence.
- He was appointed to act as the executor.
- Maybe I can act as a messenger for you.
- It is hoped that the tax cuts will act as a stimulant to further economic growth.
- A group of people gathered to plan or discuss an issue, judge a contest, or act as a team on a radio or television quiz program.
- A person legally appointed by another to act as his or her agent in the transaction of business, specifically one qualified and licensed to act for plaintiffs and defendants in legal proceedings.
- The forest will act as a defense against desert dust.
- The dean of the school act as marshal of graduation ceremony.
- act as act like
乍然看来，act as和 act like是两个同义短语，在涵义上无甚区别可言，其实不然。
- act as:act as意思是“充当”、“担任”，相当于 serve as，可与人或物词如：doctor、director、interpreter、guide、coach、 teacher、go-between、furniture、tools等字搭配使用。as是连词，引导一个省略了谓语的状语从句。例：This herb can act as an antidote against snakebite．这种药草可以用作蛇咬的解毒药。
- Last summer she acted as a guide for tourists．
- This coin may act as a screwdriver．
- Mr．Liu acted as group leader while Mr．Zhang was ill．
- act like:act like意思是“行为像”、“举动像”，相当于英语的 to act in the manner of，它常与人或动物名词连用。like是介词，其后接宾语。
- That child acts like a grown-up．
- Don't act like a fool！
- 他拒绝了我们的建议，真使我们扫兴。（注：a wet blanket 作“令人扫兴的事或人”。）
- His refusal of our offer acted like a wet blanket．